The present invention relates to EMIT systems. Specifically, the invention pertains to apparatus and method in which multi-frequency microwave in combination with preferably low frequency is structured to generate a multi-source externally focussed microwave for tissue ablation. The invention includes several versions of EMIT systems differentiated on the basis of frequency levels. Further, the invention includes a computer implemented software specifically configured and tailored to the EMIT system with a graphical and three-dimensional tomographic imaging interface.
Microwave tomography is a relatively new technology with enormous potential for use in the medical and related industries. Specifically, the technology is becoming prominently mature and practicable for use in internal, non-invasive, real-time imaging of the physiologic properties of tissues and organs, based on tissue dielectric properties differentiation.
Prior art microwave tomographic imaging utilizes microwave radiation to image an object by detecting the effects the object had on the microwave beam after it has encountered the object. The changes effected in the reflected microwave, due to this encounter, are dependent upon the dielectric permittivity and conductivity properties of the tissues of the object being imaged. Specifically, for a given microwave frequency, the observed changes in the reflected microwave echo signify a specific signature of the imaged tissue.
Microwaves are ultra-high to super-high frequency radio waves with very short wavelengths ranging from approximately 130 centimeters down to fractions of a millimeter. Frequencies range between 0.1 Giga Hertz (GHZ) to 3000 GHZ. The microwave range which is currently used for microwave imaging of biological tissues is in the range of 0.5 to about 3 GHZ. However, other ranges of the microwave spectrum may also be used as well. The determinant in the selection of the range is that the radiation be non-ionizing to prevent destruction of tissue members or cells. Accordingly, there are biophysical parameters which should be considered when determining a compatible frequency range.
The prior art utilizes two basic categories of microwave imaging. The first category is static imaging based on forming images by determining the absolute permittivity values of the microwave radiation after its interaction with the object. The second category is dynamic imaging which is based on variations in permittivity within the object occurring at the time of incidence of the microwave radiation. The latter form of imaging is extremely useful in applications in imaging biological tissues to monitor ongoing physiological change. Both static and dynamic imaging techniques require an active imaging process whereby a microwave scanner employs moving or scanning incident radiation and detects the changes in the microwave radiation based on interaction with the object being imaged.
Using dynamic imaging, image reconstruction is based on the difference in diffracted fields recorded from several data sets taken from a body with a changing dielectric contrast. However, internal imaging within larger bodies poses resolution problems which limit the application and scope of dynamic imaging. The present invention, including the related disclosures attached herewith, provide significant advances over the prior art by integrating biophysical, computer software and microwave tomography technologies to provide a high resolution image.
The invention integrates and implements biophysical, algorithmic/computer and microwave tomography devices and method to provide a three-dimensional tomographic system. Specifically, the invention includes a new method and system for medical physiological tomography wherein a one frequency three dimensional microwave tomographic system (3D MWT) is combined with one frequency three dimensional electrical impedance tomographic system (3D EIT) capable of imaging a full scale biological object(s) such as a human torso.
Specifically, the present invention provides an internal, non-invasive, real time imaging of the physiologic properties and temporal changes of tissues and organs based on tissue dielectric properties differentiation. For example, using the invention it has been shown that the dielectric properties of the myocardium are sensitive indicators of its physiological condition, including local blood supply, ischemia and infarction. The degree of change in the myocardial dielectric properties provides adequate data for reconstruction using microwave tomography. More specifically, the invention includes an EMIT system with a number of microwave frequencies (microwave spectroscopy) and one frequency (about 0.2 MHZ) lower than the cellular membrane relaxation frequency. This frequency composition of the invention enables estimation of biophysical parameters of the tissue as cellular volume fraction, intracellular and membrane resistivities, cell membrane capacitance, tissue free and bound water content and tissue temperature. It should be noted that such information is critical not only for cardiology but also for other branches of medicine, inter alia, oncology, urology, neurology and (preliminary information) HIV studies.
Further, the present invention provides mathematical models and computer implemented algorithms for constructing heretofore unavailable quantitatively reconstructed clear structural images which depict exact distribution of dielectrical properties within an object.
Furthermore, the present invention provides a therapeutic device providing internal local overheat of the tissue by electromagnetic energy focusing.